With development of communications technologies, more terminals need to access a wireless network, and consequently it is difficult for the network to fixedly allocate resources for all terminals to transmit data. Therefore, all the terminals transmit data by sharing some resources, for example, the terminals transmit data in a non-contention based manner. The non-contention based manner is also referred to as a scheduling-based manner in which a terminal transmits data after obtaining a dedicated resource allocated by a base station. However, in the manner, a large quantity of signaling interactions are required, and consequently overheads are relatively high, and transmission efficiency is relatively low. In this background, a contention-based manner is put forward. The contention-based manner is also referred to as a non-scheduling based manner in which a resource used by a terminal to transmit data is not a dedicated resource but a resource shared by a plurality of terminals.
In the prior art, a terminal determines to use the contention-based manner or the non-contention based manner for transmitting data. However, the terminal does not know a current network status when determining a transmission mode, and consequently the determined transmission mode may be inappropriate.